The best outdoor window sealant is a 100% silicone or polyurethane-based caulk due to their superior durability, flexibility, and resistance to weather, UV rays, and temperature changes. For a long-lasting, waterproof seal, 100% silicone is ideal, while polyurethane offers exceptional durability and is also resistant to UV and harsh conditions. Other options include acrylic latex (easy to use but less durable) and hybrid polyurethane sealants, which are a versatile and flexible choice.
- 100% Silicone:
- Why it’s best:
- Example product: GE Supreme Silicone.
- Polyurethane-based sealants:
- Why it’s best: Highly durable and versatile, especially for areas exposed to harsh conditions or heavy use. It forms a strong, weather-resistant, and UV-resistant seal. It can have a longer curing time, so plan accordingly.
- Example product: Loctite PL Window Door & Siding Polyurethane Sealant.
- Hybrid Polyurethane Sealants:
- Why it’s best: Often recommended for use during the installation of windows, particularly vinyl ones, as they have great elasticity to expand and contract with the window without cracking.
- Example product: Nexoflex.
- Paintable silicone and silicone-blend caulks:
- Why it’s best: A good option if you need to paint over the caulk for a seamless look.
- Note: Choose a product specifically labeled as paintable.
Other considerations
- Acrylic Latex Sealants: Easy to apply and clean up, but are not as durable as silicone or polyurethane and are best for interior projects.
- For fast-drying applications: If you need a sealant that dries quickly for a faster finish, look for products like Sherwin Williams 1050 QD and Powerhouse, which are designed for rapid curing.
- For high-movement areas: Products like BigStretch are designed for flexibility in areas that may see more movement and settling.
- modernize.com
- loctiteproducts.com
- magicwindow.ca
- homedepot.com
- 4feldco.com
- youtube.com
- reddit.com
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